Cupola exhaust apparatus

ABSTRACT

AN EXHAUST ARRANGEMENT FOR A METALLURGICAL CUPOLA INCLUDING A CAP FOR A CUPOLA STACK OUTLET, THE CAP HAVING A PLENUM CHAMBER DISPOSED THEREIN EXHAUSTED TO A SYSTEM BELOW ATMOSPHERE PRESSURE, THE PLENUM CHAMBER BEING IN COMMUNICATION WITH THE PERIPHERAL SEAL BETWEEN THE CAP AND STACK OUTLET TO FACILITATE REMOVAL OF ANY STACK GAS LEAKAGE, THE CAP BEING FLOATINGLY MOUNTED TO PERMIT MORE EFFECTIVE SEALING WITH THE STACK OUTLET.

United States Patent inventor Robert G. Huntington [56] Louisville, Ky.

Appl. No. 801,666

Filed Feb. 24, 1969 Patented June 28, 1971 6 41 Assignee American AirFilter Company, Inc. 2'778442 Louisville, Ky.

References Cited UNITED STATES PATENTS 3/1928 lpsen 110/173 8/1936Mawhinney et al. 110/173 2/1954 Ekstrom 266/31 1/1957 Jenkins et al.266/31 Primary Examiner-Gerald A. Dost Attorney Ralph 8. Brick CUPOLAEXHAUST APPARATUS 3 Claims, 5 Drawing Figs.

US. Cl

31, 34, 38, 39; 1 10/173 (A), (inquired) ABSTRACT: An exhaustarrangement for a metallurgical cupola including a cap for a cupolastack outlet, the cap having a plenum chamber disposed therein exhaustedto a system below atmosphere pressure, the plenum chamber being incommunication with the peripheral seal between the cap and stack outletto facilitate removal of any stack gas leakage, the cap being floatinglymounted to permit more effective sealing with the stack outlet.

PATENTEU JUN28 I97! ATTORNEY CUPOLA EXHAUST APPARATUS BACKGROUND OF THEINVENTION The present invention pertains to an improved metallurgicalfurnace offtake, and more particularly, to a new, useful and unobviouscap arrangement for a cupola stack outlet.

Various types of arrangements are provided for offtakes of metallurgicalcupolas to ensure that during normal operations the exhaust stack isclosed to ambient atmosphere so that dirty gases emitted from the cupolaare passed from the cupola stack through a main gas offtake to suitablegas scrubbing devices. For the most part, these past arrangements haveproven to be complex and expensive in construction and maintenance, andhave presented problems in leakage in the areas where the cap engagesthe cupola stack outlet.

SUMMARY OF THE INVENTION The present invention, recognizing that thesepast cupola cap arrangements have been difficult in construction andmaintenance and have presented leakage problems, provides a uniquevented cupola cap which is straightforward and economical in bothconstruction and operation, allowing quick installation and removal withminimum leakage when the cap is in its closed position, assuring thatany exhaust gas leakage which might occur is carried off rapidly to apreselected destination. At the same time, the present inventionprovides an arrangement which permits utilization of a comparativelylight cap'for sealing purposes, the cap being floatingly mounted toinsure more effective sealing, and being so constructed with aninternally disposed plenum chamber to permit cooling of the cap duringnormal operations.

Various other features of the present invention will become obvious toone skilled in the art upon reading the disclosure set forth herein.

More particularly, the present invention provides an exhaust arrangementfor a metallurgical cupola comprising: cupola stack means having a maingas ofitake and an ambient atmosphere stack outlet; removable cap meansfor the stack outlet, the peripheral edge of the cap means engaging withthe peripheral edge of the stack means providing a peripheral seal toclose the stack means from ambient atmosphere during normal cupolamelting operations, the cap means having a plenum chamber disposedtherein in communication with the peripheral seal between the cap meansedge and the stack outlet edge; and duct ofl'take means in communicationwith the plenum chamber, the duct offtake means being connected to apressure source below atmospheric to facilitate removal of any stack gasleakage. In addition, the present invention provides a cap meansincluding a seal wall floatingly suspended in spaced relation from alift wall to define the plenum chamber therebetween, the seal wallengaging in peripherally sealed relation with the peripheral edge of thestack means outlet.

It is to be understood that various changes can be made in the severalparts of the structure disclosed herein without departing from the scopeor spirit of the present invention.

Referring to the drawing which discloses one advantageous embodiment ofthe present invention:

FIG. 1 is a plan view of the novel cupola cap arrangement;

FIG. 2 is a cross-sectional side elevation view of the apparatus of FIG.1 and a portion of the cupola stack;

FIG. 3 is an enlarged elevational view disclosing details of thefloating cap arrangement of FIGS. 1 and 2; and

FIG. 4 is an enlarged side view of the details of FIG. 3; and,

FIG. 5 is a cross-sectional side elevation view taken in a plane passingthrough line 5-5 of FIG. 1.

Referring to FIG. 2 of the drawing, cupola stack 2 is disclosedincluding refractory brick lining 3 and metal liner 4. As known in theart, cupola stack 2 is provided with main gas offtake 6 leading to asuitable gas scrubbing apparatus (not shown) and to an ambientatmosphere stack outlet 7.

Provided to close stack outlet 7 during normal furnace meltingoperations is removable cap member 8. Cap member 8, in

accordance with the present invention, includes lift wall 9 connected atthe end of pivotally mounted cantilever beam 11, suitable strengtheningrib members 12 extending from cantilever beam 11 and being fastened tothe upper portion of lift wall 9 to strengthen such lift wall. Theopposite end of cantilever beam 11 is provided with counterweight 13,the beam being pivotally mounted for removable displacement of the liftwall by means of shaft 14, the ends of which are rotatably mounted inspaced bearing blocks 16.

Extending in fixed manner from the lower face of lift wall 9 are aplurality of spaced support arms 17. Support anns l7 serve to supportcap wall 18 in a floating manner. To accomplish this, each of thesupport arms 17 is provided with a longitudinally extending slot 19;each support arm 17 extends intermediate a pair of spaced connectingarms 21 which are fastened to cap wall 18 and which pair of arms 21 havea pin 22 extending normal therebetween and through slot 19 of supportarm 17 to thus support cap wall member 18 in spaced floating arrangementfrom lift wall member 9 and to provide plenum chamber 23 therebetween.Mounted to the lower portion of the cap wall 18 is a suitable refractorylining 24, the cap wall and refractory being sized and adapted to engagewith the upper portion of the refractory brick lining of the stackoutlet 7 to provide a peripheral seal between the stack outlet and theambient atmosphere, this seal communicating with plenum chamber 23. As afurther seal arrangement, wall 26 is provided along the periphery oflift wall 9 to extend downwardly around plenum 23, the peripheral wall26 being provided with sealing lip 27 extending normally therefrom whichengages with sealing lip 28 of peripheral wall member 29 surroundingstack outlet 7 of the cupola. It is to be noted that the seal formedbetween the two lips 27 and 28 also is in communication with plenumchamber 23.

As will be noted in FIG. I of the drawing, plenum chamber 23 of capmember 8 is provided with an offtake duct 31, which in turn is connectedat break flange 32 to duct 33, the duct 33 leading to a suitable area 35in the metallurgical system having a pressure less than atmospheric,such as between the quencher and the scrubber.

With the arrangement aforedescribed, it can be seen that cap 8 issuitably ventilated for any leakage around the peripheral seal formedbetween liner 24 and stack outlet 7 and any leakages which may occuraround the ambient seal formed between lips 27 and 28, the exhaust gasesbeing carried off to a preselected destination through plenum chamber 23to cool cap 8 from the hot impact gases.

I claim:

1. An exhaust arrangement for a metallurgical cupola comprising: cupolastack means having a main gas offtake and an ambient atmosphere stackoutlet; removable cap means for said stack outlet, the peripheral edgeof said cap means engaging with the peripheral edge of said stack meansproviding a peripheral seal to close said stack means from ambientatmosphere during normal cupola melting operations, said cap meanshaving a plenum chamber disposed therein on communication with theperipheral seal between said cap means edge and said stack outlet edge;and duct offiake means in communication with said plenum chamber, saidduct offtake means being connected to a pressure source belowatmospheric pressure to facilitate removal of any stack gas leakage.

2. The apparatus of claim 1, said cap means including a lift wall and aseal wall, said seal wall being floatingly suspended in spaced relationfrom said lift wall to define said plenum chamber, the peripheral edgeof said seal wall engaging in peripherally sealed relation with theperipheral edge of said stack means outlet.

3. The apparatus of claim 2, said lift wall having a peripheral sidewalldepending therefrom including a sealing lip extending from the lowerportion thereof, said stack outlet having a sealing lip extending aroundthe outer periphery thereof to sealingly mate with the sealing lip ofsaid sidewall, said plenum of said cap means communicating with saidsealing lip to facilitate removal of any ambient atmosphere leakage.

